90243-59-7Relevant articles and documents
Palladium(II) Complexes Based on N,S-Donor Ligands: Synthesis and Molecular Structures
Khan,Khan,Noor,Schwarz
, p. 159 - 167 (2019)
Phenyl(chloro)dithioformate is treated with pyrazole derivatives and phenyl(Pz-1-carbodithioate) ligands (Pz = pyrazole (1), 3-methylpyrazole (2), and 3,5-dimethylpyrazole (3)) are obtained. These ligands are treated with PdCl2 in acetonitrile and complexes of the general formula Pd(L)Cl2 form in an essentially quantitative yield. The ligands are found to be N,S-bidentate linkers, and 5-membered palladacycles are obtained. Precursors 1–3 are oily materials and characterized by 1H and 13C NMR spectroscopy. Due to a partial solubility of Pd complexes, the complete set of NMR data cannot be collected. The structural elucidation is also accompanied by elemental and mass spectrometric analyses. Solid-state structures of complexes 5 and 6 are determined by X-ray diffraction. The data obtained for complexes 5 and 6 are also calculated by DFT using the TURBOMOLE program package. Experimental and calculated data sets are found to be in close agreement with each other.
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
supporting information, p. 4876 - 4894 (2021/09/20)
Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
Synthesis of meso-tetraarylthienylporphyrins by Suzuki-Miyaura cross-coupling reaction and studying their UV-Vis absorption spectra
Elghamry, Ibrahim,Abdelsalam, Mamdouh,Al-Faiyz, Yasair,Al-Gadry, Meshail,Al-Taysan, Norah
, p. 322 - 337 (2021/02/12)
meso-Tetra(5-arylthien-2-yl)porphyrins and their copper complexes were synthesized by two different approaches using Suzuki-Miyaura cross-coupling reactions. The first, involving the formation of 5-arylthien-2-yl carbaldehydes, followed by condensation with pyrrole. The second is a direct process that involves the coupling of meso-tetra (5-bromothien-2-yl) porphyrins with the arylboronic acids. The yield of the second approach (40-50 %) was higher than the first approach (28-35 %). The UV-Vis absorption spectra of the synthesized porphyrins revealed bathochromic shifts when compared with the parent porphyrin. Additionally, the products showed no aggregation behaviour in solution (DCM), giving a linear correlation between absorption intensity and the concentration.
Carbazolyl-bis(triazole) and Carbazolyl-bis(tetrazole) Complexes of Palladium(II) and Platinum(II)
Samanta, Samya,Zheng, Cameron,Gajecki, Leah,Berg, David J.,Oliver, Allen G.,Crosby, Tristan,Godin, Logan,Sandhu, Jaylene
, p. 983 - 1008 (2021/02/16)
The synthesis of several carbazole-bis(triazole) (CzTrR) and carbazole-bis(tetrazole) (CzTR) ligands (5a–d and 6a–d, respectively, where R=Me (a), i–Pr (b), Bz (c) and CH2-2,4,6-C6H2Me3 (d)) is reported. Reaction of these ligands with PdCl2 in refluxing acetonitrile affords the complete series of square planar complexes, Pd(CzTrR)Cl (7a–d) and Pd(CzTR)Cl (8a–d). The analogous platinum complexes are prepared by deprotonation of ligand carbazole nitrogen under nitrogen followed by reaction with Pt(COD)Cl2 to give Pt(CzTrR)Cl (9b, 9d) and Pt(CzTR)Cl (10b, 10d). The X-ray structure of several ligands (5b, 5c, 6c) and their metal complexes (8b, 8d, 9b) are reported. Complexes 7–10d were examined by cyclic voltammetry and DFT calculations to shed light on their electronic structures. The Pd and Pt complexes of the same ligand (CzTr: 7d, 9d; CzT: 8d, 10d) showed very similar oxidation potentials suggesting the lowest oxidation is ligand based. In contrast, oxidations of the tetrazole complexes 7d and 9d were notably more difficult than the triazole complexes 8d and 10d. Both of these observations are supported by DFT calculations that indicate the HOMO is essentially carbazole π-bonding in character.
A ferrocene-templated Pd-bearing molecular reactor
Gunka, Piotr A.,Kasprzak, Artur
supporting information, p. 6974 - 6979 (2020/06/04)
High-yield, chromatography-free syntheses of a ferrocene-templated molecular cage and its Pd-bearing derivative are presented. The formation of a symmetric cage-type structure was confirmed by single-crystal X-ray diffraction analysis. The Pd-bearing cage was used as an innovative catalyst for the efficient synthesis of 1,1'-biphenyls under mild conditions. The presented catalyst is reusable and 1,1'-biphenyls can be obtained efficiently in a gram scale process.
Synthesis, structural, vibrational and DFT investigation of new binuclear molecular Pd–Cu and Cu–Cu complexes formed by Schiff base and hexafluoroacetylacetonate building blocks
Basova, Tamara V.,Kovaleva, Evgenia A.,Krasnov, Pavel O.,Morozova, Natalya B.,Nikolaeva, Nataliya S.,Smolentsev, Anton I.,Sukhikh, Alexander A.,Vikulova, Evgeniia S.
, (2020/05/05)
In this work, the first binuclear molecular noble metal-contained complex from the Schiff base (SB) and β-diketonate building blocks, viz. [Pd(acacen)Cu(hfac)2], has been synthesized and investigated in comparison with the homometallic binuclear analog [Cu(acacen)Cu(hfac)2]. The detailed comparative characterization of the structure of these new compounds as well as their molecular SB components [M(acacen)] was performed using crystallography, vibrational spectroscopy and DFT calculations. Experimental IR bands have been assigned based on DFT calculations. The Hirshfeld surface analysis was used as a tool for the better insight into intermolecular contacts. It was shown that despite both bimetallic complexes had similar molecular structure and packing style, the nature of the closest intermolecular contacts in [M(acacen)Cu(hfac)2] differed considerably. A topological analysis of the electron density distribution in [M(acacen)] and [M(acacen)Cu(hfac)2] complexes was carried out and the most probable paths of bond cleavage during decomposition of the compounds were revealed. The binding energies of the molecular components in binuclear complexes were also calculated.
Transmetallation of Bis(6-diphenylphosphinoacenaphth-5-yl)-Mercury and -Tributyltin with Precious Metal Chlorides
Furan, Sinas,Lork, Enno,Mebs, Stefan,Hupf, Emanuel,Beckmann, Jens
, p. 856 - 865 (2020/05/18)
The reaction of bis(6-diphenylphosphinoacenapht-5yl)mercury, (6-Ph2P-Ace-5-)2Hg, with [(CO)2RhCl]2 and PtCl2 proceeded with extrusion of mercury / mercury(I) chloride and provided the octahedral rhodium and platinum complexes (6-Ph2P-Ace-5-)2Rh(CO)Cl and (6-Ph2P-Ace-5-)2PtCl2, respectively. The reaction of the (6-diphenylphosphinoacenapht-5yl)stannane 6-Ph2P-Ace-5-SnBu3 with PdCl2 gave rise to tributyltin chloride and a dimeric arylpalladium chloride [(6-Ph2P-Ace-5-)PdCl]2 with a planar Pd2Cl2 core. Together with the previously known gold(III) complex cis- and trans-[R2Au][Cl], the newly prepared compounds were investigated by DFT calculations. The fully optimized gas-phase structure of [(6-Ph2P-Ace-5-)PdCl]2 gives rise to a bend Pd2Cl2 core featuring a Pd···Pd palladophilic interaction. The bonding situation was studied using a set of real-space bonding indicators (RSBIs) derived from the methods Atoms-In-Molecules (AIM), Electron Localizability Indicator (ELI-D) and Non-Covalent Interaction (NCI) index.
Palladium(II)-Catalyzed Aminotrifluoromethoxylation of Alkenes: Mechanistic Insight into the Effect of N-Protecting Groups
Chen, Chaohuang,Chen, Pinhong,Hou, Chuanqi,Liu, Guosheng
supporting information, p. 346 - 350 (2020/05/25)
An efficient palladium-catalyzed regioselective 5-exo aminotrifluoromethoxylation of alkenes has been established herein, which provides a practical route towards the synthesis of OCF3-containing pyrrolidines. tert-Butyloxycarbonyl (Boc) as an amino protecting group plays a significant role in both the chemo- and regioselectivities. In addition, preliminary mechanistic studies reveal that the amino protecting group of substrates and the counter anion of palladium catalyst play critical roles in reaction efficiency presumably due to an isomerization of alkyl- Pd(II) intermediates. Moreover, the asymmetric 5-exo aminotrifluoromethoxylation reaction has also been achieved by introducing a sterically bulky pyridinyl-oxazoline ligand.
Functional hexanuclear Y(III) cluster-based MOFs supported Pd(II) single site catalysts for aerobic selective oxidation of styrene
Han, Zheng-Bo,Wei, Na,Xing, Zhiqiang,Zhang, Yue
, (2020/06/10)
Oxidation of styrene is one of the significant reactions in organic synthesis. In this work, a serious of PdCl2 moiety-decorated Y6-MOFs adopting post-synthetic strategy were fabricated as applicable single-site catalysts for oxidation of styrene. Specifically, the functional organic linker, H2bpydc (2,2′-bipyridine-5,5′-dicarboxylic acid), was first incorporated quantitatively into Y6 clusters-based MOF, [(CH3)2NH2]2[Y6(μ3-OH)8(bpdc)6] (bpdc = 4,4′-biphenyl dicarboxylic acid) via post-synthetic ligand exchange. Then post-synthetic Pd(II) metalation was performed to enhance the density of isolated single sites. The obtained Pd(II)-Y-bpydcx/bpdc1-x can be used as highly efficient heterogeneous single-site catalysts to promote selective oxidative cleavage of styrene to benzaldehyde using O2 as a oxidant under solvent-free and mild reaction conditions (1 atm and 80 °C). Importantly, when using Pd(II)-Y-bpydc0.8/bpdc0.2 (0.024 mmol Pd) as catalyst, the high conversion of styrene and the selectivity for benzaldehyde can reach 88.7 % and 82.2 %, respectively.
Catalytic C–C cross-coupling and hydrogen evolution by two Pd(II)-complexes of di-2-pyridyl ketone benzoyl hydrazones
Bakir, Mohammed,Lawrence, Mark W.,Nelson, Peter,Yamin, M. Bohari
, p. 2261 - 2278 (2019/08/12)
The reactions between [PdCl2(CH3CN)2] and dpk-h [dpk-h = di-2-pyridyl ketone benzoyl hydrazone (dpkbh) or di-2-pyridyl ketone 4-aminobenzoyl hydrazone (dpk-4-abh)] at room temperature in air produced [PdCl2(κ3-Npy,Nim,O-dpkbh)] (1) and PdCl2(κ3-Npy,Nim,O-dpk-4-abh)] (2). X-ray structural analysis on a single crystal of PdCl(κ3-N,N,O-dpk-4-abh-H)]·H2O·dmf (3) established its authenticity, points to keto-enol tautomerization due to solvent-compound interactions and revealed pseudo-coordination of the carbonyl group to the Pd ion. Solid-state infrared measurements confirmed the pseudo coordination of the carbonyl group of dpk-h as evident from the appearance of the ν(C=O) of coordinated dpk-h in close proximity to the ν(C=O) of uncoordinated dpk-h. 1H NMR measurements on protophilic solutions of 1 and 2 disclosed solvent dependence and keto-enol tautomerization while variable temperature studies established the predominance of the keto form. The electronic absorption spectra of 1 and 2 measured in protophilic solvents confirmed the coordination of the Pd ion to dpk-h as evident from the appearance of d-d and ligand based electronic transitions. The catalytic C–C cross-coupling reactions and electro-catalytic behavior of 1 and 2 toward a proton reduction were investigated and revealed good catalytic properties. Overall rate constants (kapp) for the electrocatalytic H2 evolution of (3.39 ± 0.3) × 103 and (4.04 ± 0.2) × 103 M?1 s?1 were estimated and overpotentials of 157 and 67 mV, and turnover numbers (TON) of 2.0 and 3.2 for 1 and 2, respectively, were determined.
